Differential Diagnosis for a 44-year-old Male with Abrupt Onset of Redness, Swelling, and Tenderness in the 2nd Digit and Surrounding Forefoot Area

• Single Most Likely Diagnosis
  • Cellulitis: This is the most likely diagnosis given the symptoms of redness, swelling, and tenderness in a localized area. Cellulitis is a common bacterial skin infection that can cause these symptoms, especially in the lower extremities.
• Other Likely Diagnoses
  • Paronychia: An infection of the skin around the nail, which could cause redness, swelling, and tenderness, particularly if the infection is severe and involves the surrounding soft tissues.
  • Ingrown Toenail: This condition can cause localized redness, swelling, and tenderness, especially if it becomes infected.
  • Gout: Although gout typically affects the first metatarsophalangeal joint, it can occasionally affect other toes and present with acute onset of redness, swelling, and tenderness.
• Do Not Miss Diagnoses
  • Osteomyelitis: A bone infection that could present with localized redness, swelling, and tenderness. It's crucial to consider this diagnosis because untreated osteomyelitis can lead to serious complications.
  • Septic Arthritis: An infection within a joint, which could cause severe pain, redness, swelling, and tenderness. Early diagnosis and treatment are critical to prevent joint destruction.
  • Deep Vein Thrombosis (DVT): Although less common in the forefoot, DVT could cause swelling and tenderness. It's a critical diagnosis to consider due to the risk of pulmonary embolism.
• Rare Diagnoses
  • Erythema Elevatum Diutinum: A rare skin condition characterized by red, swollen, and tender lesions, typically on the extensor surfaces of the extremities.
  • Sarcoidosis: A systemic disease that can cause skin lesions, including those on the feet, although this would be an unusual presentation.
  • Complex Regional Pain Syndrome (CRPS): A condition characterized by intense burning or aching pain in the hands or feet after an injury or trauma, which could potentially cause localized redness and swelling.